Each year, about 390,000 new cases of oral cancer are diagnosed worldwide. Mortality from oral cancer is high in both developed and developing countries, with approximately 207,000 deaths per year usually after devastating disfiguration and loss of vital functions such as swallowing and breathing. Despite advances in therapy, the 5-year survival rate has not improved significantly due to often advanced stage at diagnosis. Therefore, prevention, identification of high-risk populations and early diagnosis are the most important ways to control oral cancer. The oral mucosa is exposed to numerous factors. However, existing preventive strategies against oral cancer have been focused on tobacco and alcohol use only. Chronic infections have been shown to influence carcinogenesis. Periodontitis, a chronic oral infection, may play a key role in the etiology of oral cancer. Periodontitis is caused by inflammatory reactions to microorganisms in the dental plaque leading to destruction of tissues around the teeth including alveolar bone. A causal relationship between periodontitis and oral cancer is biologically plausible. Surprisingly, studies assessing this relationship are lacking. Our long-term objective is to determine the role of periodontitis on the incidence of oral cancer. The specific aim of the proposed study is to test whether alveolar bone loss (ABL), a radiographic outcome measure of periodontitis, is associated with an increased risk of oral cancer. We will utilize existing patient records at the Department of Dentistry and Maxillofacial Prosthetics, Roswell Park Cancer Institute. Patients admitted between June 15, 1999 and January 10, 2005 will be eligible excluding children, edentulous and those with prior radiotherapy or chemotherapy. A case-control study design will be used to compare oral cancer cases to controls with no cancer by the severity of ABL. We will use multiple logistic regression analysis to estimate independent effect of ABL on the incidence of oral cancer adjusting simultaneously for other risk factors of oral cancer such as tobacco, alcohol, age, gender and race/ethnicity. The significance of this study is substantial. New information will be gained providing insight into the etiology of oral cancer in a cost-effective way, using existing data. If an association between periodontitis and oral cancer exists, subjects with periodontitis could be screened for oral cancer as a "high-risk population" and survival from oral cancer could be improved by early diagnosis. Prevention of oral cancer could begin with prevention and early treatment of periodontitis. [unreadable] [unreadable] [unreadable]